A 61-year-old man with recurrent supraglottic small-cell carcinoma after radiotherapy, chemotherapy and radical neck dissection had a head MRI which showed a cerebellar metastatic lesion. The patient had normal cerebellar function, but the lesion impinged on the roof of the fourth ventricle, and impending obstruction of cerebrospinal fluid circulation threatened to kill the patient before the time left from the small cell carcinoma. It was elected to surgically extirpate the lesion.